There has conventionally been a biosensor in which a sample is introduced into a cavity from a front-end suction port by a capillary phenomenon.
A disposable biosensor 100 shown in FIG. 6(b) is detachably attached to a measurement device 200. The biosensor 100 is composed of a cover 11, a spacer 12, and a base plate 17 which are bonded together as shown in an exploded perspective view of FIG. 6(a). A sensor electrode 15 on the substrate 17 comprises a working electrode and a counter electrode, and determines the quantity of a base substance by measuring an oxidation or reduction current value which is caused by a voltage applied between the counter electrode and the working electrode. In FIG. 6, reference numeral 13 denotes a capillary for soaking up blood, and reference numeral 18 denotes an air port which enables this soaking-up.
The conventional biosensors as described above have been disclosed in the following documents.
Patent Document 1: Japanese Published Patent Application No. 2004-245836
Patent Document 2: Japanese Published Patent Application No. 2003-4691
Patent Document 3: Japanese Published Patent Application No. Hei. 8-304340
Patent Document 4: International Publication WO 99/60391
Patent Document 5: National Publication of Translated Version No. 8-502589